Effect of polymer modified cementitious coatings on water and chloride permeability in concrete

Concrete coatings are widely used to improve durability of reinforced concrete structures in order to prevent and control reinforcement corrosion in chlorides containing environment. Cement-based coatings, as well as organic-based coatings, act as a physical barrier to the penetration of water, ions and gases. In this paper, the permeability of concrete, coated with commercial polymer-modified cementitious mortars with two different polymer-to-cement ratios, to water and chlorides was evaluated as a function of water absorption, chloride diffusion, chloride penetration rate and coating adhesion properties. Tests were performed on coated concrete specimens as well as on coating layers. The effect of physical barrier to chloride penetration and the ability to decrease water content into concrete were discussed, as well as the influence on the service life of reinforced concrete structures.